Bruce Griffiths skrev: > Magnus > > For examples of the use of crystals in filters for cleaning up the > output of a crystal oscillator look at the circuit schematics for some > of the early crystal frequency standards. > Crystal filters were used quite liberally in some of these to clean up > the outputs.
It's used in the step-up chain of the SR620 for instance. The SR620 has a 10 MHz oscillator (TCXO or as in my case a Wenzel OCXO) which is stepped up to 90 MHz using a fairly ordinary odd-order stepup and filtering chain. The ECL logic counter frontend use this as coarse counter frequency. The analog interpolators is a bit interesting in a few peculiarities but nothing really exciting. The crystal filters of that chain is setup in PI-filter style with the crystals in serial mode. > However it may be necessary to control the temperature of these crystals. Indeed. I wonder if he really needs that level of sine purity. An LC tank should be sufficient to get started. Cheers, Magnus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
